C++ QTextBlock::length方法代码示例

void ClangFormat::formatAtCursor()
{
    const TextEditor::TextEditorWidget *widget
            = TextEditor::TextEditorWidget::currentTextEditorWidget();
    if (!widget)
        return;

    const QTextCursor tc = widget->textCursor();
    if (tc.hasSelection()) {
        const int offset = tc.selectionStart();
        const int length = tc.selectionEnd() - offset;
        BeautifierPlugin::formatCurrentFile(command(offset, length));
    } else {
        // Pretend that the current line was selected.
        // Note that clang-format will extend the range to the next bigger
        // syntactic construct if needed.
        const QTextBlock block = tc.block();
        const int offset = block.position();
        const int length = block.length();
        BeautifierPlugin::formatCurrentFile(command(offset, length));
    }
}

void XmlWriter::processBlock(QDomElement &parent, const QTextBlock &block)
{
    QDomElement blockElement = document->createElement("block");
    blockElement.setAttribute("position", block.position());
    blockElement.setAttribute("length", block.length());
    parent.appendChild(blockElement);

    QTextBlock::iterator it;
    for (it = block.begin(); !(it.atEnd()); ++it) {
        QTextFragment fragment = it.fragment();

        if (fragment.isValid()) {
            QDomElement fragmentElement = document->createElement("fragment");
            blockElement.appendChild(fragmentElement);

            fragmentElement.setAttribute("length", fragment.length());
            QDomText fragmentText = document->createTextNode(fragment.text());

            fragmentElement.appendChild(fragmentText);
        }
    }
}

void Changecase::upperCase()
{
    QTextBlock block = m_document->findBlock(m_startPosition);
    int pos = block.position();
    bool finished = false;
    bool foundToBeChanged = false;

    while (true) {
        QString text = block.text();
        QString result;

        QString::ConstIterator constIter = text.constBegin();
        while (pos < m_endPosition && constIter != text.constEnd()) {
            if (pos >= m_startPosition) {
                if (!foundToBeChanged && constIter->isLower())
                    foundToBeChanged = true;
                result.append(constIter->toUpper());
            }

            pos++;
            constIter++;
        }

        if (!(block.isValid() && block.position() + block.length() < m_endPosition))
            finished = true;

        if (foundToBeChanged) {
            m_cursor.setPosition(qMax(m_startPosition, block.position()));
            m_cursor.setPosition(qMin(pos, m_endPosition), QTextCursor::KeepAnchor);
            m_cursor.insertText(result);
        }

        if (finished)
            break;

        block = block.next();
        pos = block.position();
    }
}

bool QssCompletionAssistProcessor::isInComment() const
{
    QTextBlock block = m_interface->textDocument()->findBlock(m_interface->position());
    QTextBlock prevBlock = block.previous();
    QList<Token> tokenList;
    Lexer lexer;
    lexer.setScanComments(true);
    if (prevBlock.isValid())
        lexer.setState(qssLexerState(prevBlock.userState()));
    tokenList = lexer.scanMore(block.text());
    int index = m_interface->position() - block.position();
    Q_FOREACH (const Token &t, tokenList) {
        if (t.is(Token::Comment) && index >= t.begin() && index < t.end()) {
            qDebug() << "InComment";
            return true;
        }
    }
    if (index == block.length() && (lexer.state() & Lexer::MultiLineComment)) {
        qDebug() << "InComment";
        return true;
    }
    return false;
}

void QmlJSOutlineWidget::updateTextCursor(const QModelIndex &index)
{
    QModelIndex sourceIndex = m_filterModel->mapToSource(index);
    AST::SourceLocation location
            = m_editor->qmlJsEditorDocument()->outlineModel()->sourceLocation(sourceIndex);

    if (!location.isValid())
        return;

    const QTextBlock lastBlock = m_editor->document()->lastBlock();
    const uint textLength = lastBlock.position() + lastBlock.length();
    if (location.offset >= textLength)
        return;

    Core::EditorManager::cutForwardNavigationHistory();
    Core::EditorManager::addCurrentPositionToNavigationHistory();

    QTextCursor textCursor = m_editor->textCursor();
    m_blockCursorSync = true;
    textCursor.setPosition(location.offset);
    m_editor->setTextCursor(textCursor);
    m_editor->centerCursor();
    m_blockCursorSync = false;
}

QPair<int, int> getFirstAndLastVisiblePosition(Editor *editor)
{
  QTextCursor cursor = editor->textCursor();
  QTextDocument *doc = editor->document();
  int currentLine = doc->findBlock(cursor.position()).blockNumber();
  int cursorHeight = editor->cursorRect().height();
  int lineCountToFirstVisibleLine = editor->cursorRect().top() / cursorHeight;
  int firstVisibleLineNum = currentLine - lineCountToFirstVisibleLine;
  if (firstVisibleLineNum < 0) {
    firstVisibleLineNum = 0;
  }
  int maxLineNumOnScreen = (editor->viewport()->height() / cursorHeight);
  if (maxLineNumOnScreen < 1) {
    maxLineNumOnScreen = 1;
  }
  int firstPos = doc->findBlockByNumber(firstVisibleLineNum).position();
  int lastVisibleLineNum = firstVisibleLineNum + maxLineNumOnScreen - 1;
  QTextBlock lastVisibleTextBlock = doc->findBlockByNumber(lastVisibleLineNum);
  if (!lastVisibleTextBlock.isValid()) {
    lastVisibleTextBlock = doc->lastBlock();
  }
  int lastPos = lastVisibleTextBlock.position() + lastVisibleTextBlock.length() - 1;
  return QPair<int, int>(firstPos, lastPos);
}

void HGMarkdownHighlighter::highlight()
{
    if (cached_elements == NULL) {
        qDebug() << "cached_elements is NULL";
        return;
    }

    if (highlightingStyles == NULL)
        this->setDefaultStyles();

    this->clearFormatting();

    for (int i = 0; i < highlightingStyles->size(); i++)
    {
        HighlightingStyle style = highlightingStyles->at(i);
        pmh_element *elem_cursor = cached_elements[style.type];
        while (elem_cursor != NULL)
        {
            if (elem_cursor->end <= elem_cursor->pos) {
                elem_cursor = elem_cursor->next;
                continue;
            }

            // "The QTextLayout object can only be modified from the
            // documentChanged implementation of a QAbstractTextDocumentLayout
            // subclass. Any changes applied from the outside cause undefined
            // behavior." -- we are breaking this rule here. There might be
            // a better (more correct) way to do this.

            int startBlockNum = document->findBlock(elem_cursor->pos).blockNumber();
            int endBlockNum = document->findBlock(elem_cursor->end).blockNumber();
            for (int j = startBlockNum; j <= endBlockNum; j++)
            {
                QTextBlock block = document->findBlockByNumber(j);

                QTextLayout *layout = block.layout();
                QList<QTextLayout::FormatRange> list = layout->additionalFormats();
                int blockpos = block.position();
                QTextLayout::FormatRange r;
                r.format = style.format;

                if (j == startBlockNum) {
                    r.start = elem_cursor->pos - blockpos;
                    r.length = (startBlockNum == endBlockNum)
                                ? elem_cursor->end - elem_cursor->pos
                                : block.length() - r.start;
                } else if (j == endBlockNum) {
                    r.start = 0;
                    r.length = elem_cursor->end - blockpos;
                } else {
                    r.start = 0;
                    r.length = block.length();
                }

                list.append(r);
                layout->setAdditionalFormats(list);
            }

            elem_cursor = elem_cursor->next;
        }
    }

    document->markContentsDirty(0, document->characterCount());
}

QString FlatTextarea::getText(int32 start, int32 end) const {
	if (end >= 0 && end <= start) return QString();

	if (start < 0) start = 0;
	bool full = (start == 0) && (end < 0);

	QTextDocument *doc(document());
	QTextBlock from = full ? doc->begin() : doc->findBlock(start), till = (end < 0) ? doc->end() : doc->findBlock(end);
	if (till.isValid()) till = till.next();

	int32 possibleLen = 0;
	for (QTextBlock b = from; b != till; b = b.next()) {
		possibleLen += b.length();
	}
	QString result;
	result.reserve(possibleLen + 1);
	if (!full && end < 0) {
		end = possibleLen;
	}

	for (QTextBlock b = from; b != till; b = b.next()) {
		for (QTextBlock::Iterator iter = b.begin(); !iter.atEnd(); ++iter) {
			QTextFragment fragment(iter.fragment());
			if (!fragment.isValid()) continue;

			int32 p = full ? 0 : fragment.position(), e = full ? 0 : (p + fragment.length());
			if (!full) {
				if (p >= end || e <= start) {
					continue;
				}
			}

			QTextCharFormat f = fragment.charFormat();
			QString emojiText;
			QString t(fragment.text());
			if (!full) {
				if (p < start) {
					t = t.mid(start - p, end - start);
				} else if (e > end) {
					t = t.mid(0, end - p);
				}
			}
			QChar *ub = t.data(), *uc = ub, *ue = uc + t.size();
			for (; uc != ue; ++uc) {
				switch (uc->unicode()) {
				case 0xfdd0: // QTextBeginningOfFrame
				case 0xfdd1: // QTextEndOfFrame
				case QChar::ParagraphSeparator:
				case QChar::LineSeparator:
					*uc = QLatin1Char('\n');
					break;
				case QChar::Nbsp:
					*uc = QLatin1Char(' ');
					break;
				case QChar::ObjectReplacementCharacter:
					if (emojiText.isEmpty() && f.isImageFormat()) {
						QString imageName = static_cast<QTextImageFormat*>(&f)->name();
						if (imageName.startsWith(QLatin1String("emoji://e."))) {
							if (EmojiPtr emoji = emojiFromUrl(imageName)) {
								emojiText = textEmojiString(emoji);
							}
						}
					}
					if (uc > ub) result.append(ub, uc - ub);
					if (!emojiText.isEmpty()) result.append(emojiText);
					ub = uc + 1;
				break;
				}
			}
			if (uc > ub) result.append(ub, uc - ub);
		}
		result.append('\n');
	}
	result.chop(1);
	return result;
}

void Changecase::sentenceCase()
{
    QTextBlock block = m_document->findBlock(m_startPosition);
    QTextCursor backCursor(m_cursor);
    int pos = block.position() + block.length() - 1;

    // TODO
    // * Exception?
    while (true) {
        QString text = block.text();
        int prevLetterIndex = -1;
        QChar currentWord;
        pos = block.position() + block.length() - 1;

        QString::Iterator iter = text.end();

        if (text.isEmpty()) { // empty block, go to next block
            if (!(block.isValid() && block.position() + block.length() < m_endPosition))
                break;
            block = block.next();
            continue;
        }

        iter--;
        while (iter != text.begin()) {
            while (iter != text.begin() && !iter->isSpace()) {
                iter--;
                pos--;
            }

            prevLetterIndex = pos;
            currentWord = QChar(*(iter + 1));
            while (iter != text.begin() && iter->isSpace()) {
                iter--;
                pos--;
            }

            // found end of sentence, go back to last found letter (indicating start of a word)
            if (iter != text.begin() && (*iter == QChar('.') || *iter == QChar('!') || *iter == QChar('?'))) {
                if (prevLetterIndex >= m_startPosition && prevLetterIndex <= m_endPosition && currentWord.isLower()) {
                    // kDebug() <<"Found end of sentence" << *iter <<" :" << currentWord;
                    m_cursor.setPosition(prevLetterIndex);
                    m_cursor.deleteChar();
                    m_cursor.insertText(currentWord.toUpper());
                    iter--;
                    pos--;
                }
                else if (prevLetterIndex < m_startPosition)
                    break;
            }
        }

        if (iter == text.begin() && --pos >= m_startPosition) { // start of paragraph, must be start of a sentence also
            if (pos + 1 == prevLetterIndex && (*iter).isLower()) {
                m_cursor.setPosition(pos);
                m_cursor.deleteChar();
                m_cursor.insertText((*iter).toUpper());
            }
            else if (!(*iter).isLetter() && currentWord.isLower()) {
                m_cursor.setPosition(prevLetterIndex);
                m_cursor.deleteChar();
                m_cursor.insertText(currentWord.toUpper());
            }
        }

        if (!(block.isValid() && block.position() + block.length() < m_endPosition))
            break;
        block = block.next();
    }
}

int QTextDocumentPrivate::undoRedo(bool undo)
{
    PMDEBUG("%s, undoState=%d, undoStack size=%d", undo ? "undo:" : "redo:", undoState, undoStack.size());
    if (!undoEnabled || (undo && undoState == 0) || (!undo && undoState == undoStack.size()))
        return -1;

    undoEnabled = false;
    beginEditBlock();
    while (1) {
        if (undo)
            --undoState;
        QTextUndoCommand &c = undoStack[undoState];
        int resetBlockRevision = c.pos;

	switch(c.command) {
        case QTextUndoCommand::Inserted:
            remove(c.pos, c.length, (QTextUndoCommand::Operation)c.operation);
            PMDEBUG("   erase: from %d, length %d", c.pos, c.length);
            c.command = QTextUndoCommand::Removed;
	    break;
        case QTextUndoCommand::Removed:
            PMDEBUG("   insert: format %d (from %d, length %d, strpos=%d)", c.format, c.pos, c.length, c.strPos);
            insert_string(c.pos, c.strPos, c.length, c.format, (QTextUndoCommand::Operation)c.operation);
            c.command = QTextUndoCommand::Inserted;
	    break;
	case QTextUndoCommand::BlockInserted:
	case QTextUndoCommand::BlockAdded:
            remove_block(c.pos, &c.blockFormat, c.command, (QTextUndoCommand::Operation)c.operation);
            PMDEBUG("   blockremove: from %d", c.pos);
	    if (c.command == QTextUndoCommand::BlockInserted)
		c.command = QTextUndoCommand::BlockRemoved;
	    else
		c.command = QTextUndoCommand::BlockDeleted;
	    break;
	case QTextUndoCommand::BlockRemoved:
	case QTextUndoCommand::BlockDeleted:
            PMDEBUG("   blockinsert: charformat %d blockformat %d (pos %d, strpos=%d)", c.format, c.blockFormat, c.pos, c.strPos);
            insert_block(c.pos, c.strPos, c.format, c.blockFormat, (QTextUndoCommand::Operation)c.operation, c.command);
            resetBlockRevision += 1;
	    if (c.command == QTextUndoCommand::BlockRemoved)
		c.command = QTextUndoCommand::BlockInserted;
	    else
		c.command = QTextUndoCommand::BlockAdded;
	    break;
	case QTextUndoCommand::CharFormatChanged: {
            resetBlockRevision = -1; // ## TODO
            PMDEBUG("   charFormat: format %d (from %d, length %d)", c.format, c.pos, c.length);
            FragmentIterator it = find(c.pos);
            Q_ASSERT(!it.atEnd());

            int oldFormat = it.value()->format;
            setCharFormat(c.pos, c.length, formats.charFormat(c.format));
            c.format = oldFormat;
	    break;
	}
	case QTextUndoCommand::BlockFormatChanged: {
            resetBlockRevision = -1; // ## TODO
            PMDEBUG("   blockformat: format %d pos %d", c.format, c.pos);
            QTextBlock it = blocksFind(c.pos);
            Q_ASSERT(it.isValid());

            int oldFormat = block(it)->format;
            block(it)->format = c.format;
            QTextBlockGroup *oldGroup = qobject_cast<QTextBlockGroup *>(objectForFormat(formats.blockFormat(oldFormat)));
            QTextBlockGroup *group = qobject_cast<QTextBlockGroup *>(objectForFormat(formats.blockFormat(c.format)));
            c.format = oldFormat;
            if (group != oldGroup) {
                if (oldGroup)
                    oldGroup->blockRemoved(it);
                if (group)
                    group->blockInserted(it);
            } else if (group) {
                group->blockFormatChanged(it);
            }
            documentChange(it.position(), it.length());
	    break;
	}
	case QTextUndoCommand::GroupFormatChange: {
            resetBlockRevision = -1; // ## TODO
            PMDEBUG("   group format change");
            QTextObject *object = objectForIndex(c.objectIndex);
            int oldFormat = formats.objectFormatIndex(c.objectIndex);
            changeObjectFormat(object, c.format);
            c.format = oldFormat;
	    break;
	}
	case QTextUndoCommand::Custom:
            resetBlockRevision = -1; // ## TODO
            if (undo)
                c.custom->undo();
            else
                c.custom->redo();
	    break;
	default:
	    Q_ASSERT(false);
        }

        if (resetBlockRevision >= 0) {
            int b = blocks.findNode(resetBlockRevision);
            QTextBlockData *B = blocks.fragment(b);
//.........这里部分代码省略.........

void MarkdownHighlighter::highlight()
{
	if (cached_elements == nullptr) {
		// Shouldn't happen
		return;
	}

	QHash<int, QList<QTextLayout::FormatRange> > lists;
	QHash<int, QList<QTextLayout::FormatRange> >::iterator hashIter;
	QList<QTextBlock> blocks;

	this->clearFormatting();

	for (int i = 0; i < highlightingStyles.size(); i++) {
		HighlightingStyle style = highlightingStyles.at(i);
		pmh_element *elem_cursor = cached_elements[style.type];
		while (elem_cursor != NULL) {
			if (elem_cursor->end <= elem_cursor->pos) {
				elem_cursor = elem_cursor->next;
				continue;
			}

			// "The QTextLayout object can only be modified from the
			// documentChanged implementation of a QAbstractTextDocumentLayout
			// subclass. Any changes applied from the outside cause undefined
			// behavior." -- we are breaking this rule here. There might be
			// a better (more correct) way to do this.

			int startBlockNum = document->findBlock(elem_cursor->pos).blockNumber();
			int endBlockNum = document->findBlock(elem_cursor->end).blockNumber();
			for (int j = startBlockNum; j <= endBlockNum; j++) {
				QTextBlock block = document->findBlockByNumber(j);
				hashIter = lists.find(block.blockNumber());
				if (hashIter == lists.end()) {
					QList<QTextLayout::FormatRange> emptyList;
					hashIter = lists.insert(block.blockNumber(), emptyList);
					blocks.append(block);
				}
				int blockpos = block.position();
				QTextLayout::FormatRange r;
				r.format = style.format;

				if (j == startBlockNum) {
					r.start = elem_cursor->pos - blockpos;
					r.length = (startBlockNum == endBlockNum)
						? elem_cursor->end - elem_cursor->pos
						: block.length() - r.start;
				} else if (j == endBlockNum) {
					r.start = 0;
					r.length = elem_cursor->end - blockpos;
				} else {
					r.start = 0;
					r.length = block.length();
				}
				hashIter.value().append(r);
			}

			elem_cursor = elem_cursor->next;
		}
	}
	std::sort(blocks.begin(), blocks.end());
	for (auto &block : blocks) {
		hashIter = lists.find(block.blockNumber());
		std::sort(hashIter.value().begin(), hashIter.value().end(), &MarkdownHighlighter::formatLessThan);
		block.layout()->setAdditionalFormats(hashIter.value());
	}
	document->markContentsDirty(0, document->characterCount());
}

void BaseEditor::paintEvent(QPaintEvent *e)
{
    //copy from QPlainTextEditor
    QPainter painter(viewport());
    Q_ASSERT(qobject_cast<QPlainTextDocumentLayout*>(document()->documentLayout()));

    QPointF offset(contentOffset());

    QRect er = e->rect();
    QRect viewportRect = viewport()->rect();

    bool editable = !isReadOnly();

    QTextBlock block = firstVisibleBlock();
    qreal maximumWidth = document()->documentLayout()->documentSize().width();

    //margin
    qreal lineX = 0;
    if (conf->isDisplayRightColumnMargin()) {
        // Don't use QFontMetricsF::averageCharWidth here, due to it returning
        // a fractional size even when this is not supported by the platform.
        lineX = QFontMetricsF(document()->defaultFont()).width(QLatin1Char('X')) * conf->getRightMarginColumn() + offset.x() + 4;

        if (lineX < viewportRect.width()) {
            const QBrush background = QBrush(QColor(239, 239, 239));
            painter.fillRect(QRectF(lineX, er.top(), viewportRect.width() - lineX, er.height()),
                             background);

            const QColor col = (palette().base().color().value() > 128) ? Qt::black : Qt::white;
            const QPen pen = painter.pen();
            painter.setPen(blendColors(background.isOpaque() ? background.color() : palette().base().color(),
                                       col, 32));
            painter.drawLine(QPointF(lineX, er.top()), QPointF(lineX, er.bottom()));
            painter.setPen(pen);
        }
    }

    // Set a brush origin so that the WaveUnderline knows where the wave started
    painter.setBrushOrigin(offset);

    // keep right margin clean from full-width selection
    int maxX = offset.x() + qMax((qreal)viewportRect.width(), maximumWidth)
               - document()->documentMargin();
    er.setRight(qMin(er.right(), maxX));
    painter.setClipRect(er);


    QAbstractTextDocumentLayout::PaintContext context = getPaintContext();

    while (block.isValid()) {

        QRectF r = blockBoundingRect(block).translated(offset);
        QTextLayout *layout = block.layout();

        if (!block.isVisible()) {
            offset.ry() += r.height();
            block = block.next();
            continue;
        }

        if (r.bottom() >= er.top() && r.top() <= er.bottom()) {

            QTextBlockFormat blockFormat = block.blockFormat();

            QBrush bg = blockFormat.background();
            if (bg != Qt::NoBrush) {
                QRectF contentsRect = r;
                contentsRect.setWidth(qMax(r.width(), maximumWidth));
                fillBackground(&painter, contentsRect, bg);
            }


            QVector<QTextLayout::FormatRange> selections;
            int blpos = block.position();
            int bllen = block.length();
            for (int i = 0; i < context.selections.size(); ++i) {
                const QAbstractTextDocumentLayout::Selection &range = context.selections.at(i);
                const int selStart = range.cursor.selectionStart() - blpos;
                const int selEnd = range.cursor.selectionEnd() - blpos;
                if (selStart < bllen && selEnd > 0
                    && selEnd > selStart) {
                    QTextLayout::FormatRange o;
                    o.start = selStart;
                    o.length = selEnd - selStart;
                    o.format = range.format;
                    selections.append(o);
                } else if (!range.cursor.hasSelection() && range.format.hasProperty(QTextFormat::FullWidthSelection)
                           && block.contains(range.cursor.position())) {
                    // for full width selections we don't require an actual selection, just
                    // a position to specify the line. that's more convenience in usage.
                    QTextLayout::FormatRange o;
                    QTextLine l = layout->lineForTextPosition(range.cursor.position() - blpos);
                    o.start = l.textStart();
                    o.length = l.textLength();
                    if (o.start + o.length == bllen - 1)
                        ++o.length; // include newline
                    o.format = range.format;
                    selections.append(o);
                }
            }
//.........这里部分代码省略.........

void ScCodeEditor::blinkCode( const QTextCursor & c )
{
    if( !c.document() || !c.hasSelection() ) return;

    Settings::Manager *settings = Main::settings();
    QTextCharFormat evalCodeTextFormat = settings->getThemeVal("evaluatedCode");

    QTextDocument *doc = c.document();

    int startPos = c.selectionStart();
    int endPos = c.selectionEnd();
    QTextBlock startBlock = doc->findBlock(startPos);
    QTextBlock endBlock = doc->findBlock(endPos);
    startPos -= startBlock.position();
    endPos -= endBlock.position();

    // Get the bounds of visible blocks within the cursor's selection:

    QTextBlock block = firstVisibleBlock();
    int idx = block.blockNumber();
    int sidx = startBlock.blockNumber();

    QTextBlock firstBlock, lastBlock;
    firstBlock = lastBlock = block;

    QRectF geom = blockBoundingGeometry(block).translated(contentOffset());
    qreal top = geom.top();
    qreal bottom = top;
    qreal width=0;

    while(block.isValid() && bottom < viewport()->rect().height())
    {
        if(block.isVisible())
        {
            QTextLayout *l = block.layout();
            QRectF r = l->boundingRect();
            bottom += r.height();
            if(idx < sidx) {
                // Block not within the selection. Will skip it.
                top = bottom;
            }
            else {
                // Block within the selection.
                width = qMax(width, l->maximumWidth() + r.left());
            }
        }

        if(block == endBlock) break;

        block = block.next();
        ++idx;
        if(top == bottom)
            firstBlock = block;
    }

    lastBlock = block;

    if(bottom == top) {
        //qDebug("no visible block.");
        return;
    }

    // Construct a pixmap to render the code on:

    QPixmap pix( QSize(qCeil(width), qCeil(bottom - top)) );
    pix.fill(QColor(0,0,0,0));

    // Render the visible blocks:

    QPainter painter(&pix);
    QVector<QTextLayout::FormatRange> selections;
    block = firstBlock;
    int y=0;
    while( block.isValid() )
    {
        if (block.isVisible())
        {
            QRectF blockRect = block.layout()->boundingRect();

            // Use extra char formatting to hide code outside of selection
            // and modify the appearance of selected code:

            QTextLayout::FormatRange range;
            selections.clear();

            int start = 0;
            if(block == startBlock) {
                range.start = 0;
                range.length = startPos;
                range.format.setForeground(QColor(0,0,0,0));
                range.format.setBackground(Qt::NoBrush);
                selections.append(range);
                start = startPos;
            }

            range.start = start;
            range.length = (block == endBlock ? endPos : block.length() - 1) - range.start;
            range.format = evalCodeTextFormat;
            selections.append(range);

//.........这里部分代码省略.........

void MarkdownHighlighter::resultReady(pmh_element **elements)
{
    QTextBlock block = document()->firstBlock();
    while (block.isValid()) {
        block.layout()->clearAdditionalFormats();
        block = block.next();
    }

    if (!elements) {
        qDebug() << "elements is null";
        return;
    }

    // QTextDocument::characterCount returns a value one higher than the
    // actual character count.
    // See: https://bugreports.qt.nokia.com//browse/QTBUG-4841
    // document->toPlainText().length() would give us the correct value
    // but it's probably too slow.
    unsigned long max_offset = document()->characterCount() - 1;

    for (int i = 0; i < highlightingStyles.size(); i++)
    {
        HighlightingStyle style = highlightingStyles.at(i);
        pmh_element *elem_cursor = elements[style.type];
        while (elem_cursor != NULL)
        {
            unsigned long pos = elem_cursor->pos;
            unsigned long end = elem_cursor->end;

            if (end <= pos || max_offset < pos)
            {
                elem_cursor = elem_cursor->next;
                continue;
            }

            if (max_offset < end)
                end = max_offset;

            // "The QTextLayout object can only be modified from the
            // documentChanged implementation of a QAbstractTextDocumentLayout
            // subclass. Any changes applied from the outside cause undefined
            // behavior." -- we are breaking this rule here. There might be
            // a better (more correct) way to do this.

            int startBlockNum = document()->findBlock(pos).blockNumber();
            int endBlockNum = document()->findBlock(end).blockNumber();
            for (int j = startBlockNum; j <= endBlockNum; j++)
            {
                QTextBlock block = document()->findBlockByNumber(j);

                QTextLayout *layout = block.layout();
                QList<QTextLayout::FormatRange> list = layout->additionalFormats();
                int blockpos = block.position();
                QTextLayout::FormatRange r;
                r.format = style.format;

                if (/*_makeLinksClickable
                    &&*/ (elem_cursor->type == pmh_LINK
                        || elem_cursor->type == pmh_AUTO_LINK_URL
                        || elem_cursor->type == pmh_AUTO_LINK_EMAIL
                        || elem_cursor->type == pmh_REFERENCE)
                    && elem_cursor->address != NULL)
                {
                    QString address(elem_cursor->address);
                    if (elem_cursor->type == pmh_AUTO_LINK_EMAIL && !address.startsWith("mailto:"))
                        address = "mailto:" + address;
                    QTextCharFormat linkFormat(r.format);
                    linkFormat.setAnchor(true);
                    linkFormat.setAnchorHref(address);
                    linkFormat.setToolTip(address);
                    r.format = linkFormat;
                }

                if (j == startBlockNum) {
                    r.start = pos - blockpos;
                    r.length = (startBlockNum == endBlockNum)
                                ? end - pos
                                : block.length() - r.start;
                } else if (j == endBlockNum) {
                    r.start = 0;
                    r.length = end - blockpos;
                } else {
                    r.start = 0;
                    r.length = block.length();
                }

                list.append(r);
                layout->setAdditionalFormats(list);
            }

            elem_cursor = elem_cursor->next;
        }
    }

    document()->markContentsDirty(0, document()->characterCount());

    pmh_free_elements(elements);
}

void Utils::unCommentSelection(QPlainTextEdit *edit, CommentFlag flag, const CommentDefinition &definition)
{
    if (!definition.hasSingleLineStyle() && !definition.hasMultiLineStyle())
        return;

    QTextCursor cursor = edit->textCursor();
    QTextDocument *doc = cursor.document();

    if (!cursor.hasSelection() && (flag == BlockComment) ) {
        if (definition.hasMultiLineStyle()) {
            cursor.beginEditBlock();
            cursor.insertText(definition.multiLineStart());
            cursor.insertText(definition.multiLineEnd());
            cursor.movePosition(QTextCursor::Left,QTextCursor::MoveAnchor,definition.multiLineEnd().length());
            cursor.endEditBlock();
            edit->setTextCursor(cursor);
            return;
        }
    }

    cursor.beginEditBlock();

    int pos = cursor.position();
    int anchor = cursor.anchor();
    int start = qMin(anchor, pos);
    int end = qMax(anchor, pos);
    bool anchorIsStart = (anchor == start);

    QTextBlock startBlock = doc->findBlock(start);
    QTextBlock endBlock = doc->findBlock(end);

    if (end > start && endBlock.position() == end) {
        --end;
        endBlock = endBlock.previous();
    }

    bool doMultiLineStyleUncomment = false;
    bool doMultiLineStyleComment = false;
    bool doSingleLineStyleUncomment = false;

    bool hasSelection = cursor.hasSelection();
    int firstSpacesOffset = -1;

    if (hasSelection && definition.hasMultiLineStyle()) {

        QString startText = startBlock.text();
        int startPos = start - startBlock.position();
        const int multiLineStartLength = definition.multiLineStart().length();
        bool hasLeadingCharacters = !startText.left(startPos).trimmed().isEmpty();

        if (startPos >= multiLineStartLength
            && isComment(startText,
                         startPos - multiLineStartLength,
                         definition,
                         &CommentDefinition::multiLineStart)) {
            startPos -= multiLineStartLength;
            start -= multiLineStartLength;
        }

        bool hasSelStart = (startPos <= startText.length() - multiLineStartLength
                            && isComment(startText,
                                         startPos,
                                         definition,
                                         &CommentDefinition::multiLineStart));

        QString endText = endBlock.text();
        int endPos = end - endBlock.position();
        const int multiLineEndLength = definition.multiLineEnd().length();
        bool hasTrailingCharacters =
                !endText.left(endPos).remove(definition.singleLine()).trimmed().isEmpty()
                && !endText.mid(endPos).trimmed().isEmpty();

        if (endPos <= endText.length() - multiLineEndLength
            && isComment(endText, endPos, definition, &CommentDefinition::multiLineEnd)) {
            endPos += multiLineEndLength;
            end += multiLineEndLength;
        }

        bool hasSelEnd = (endPos >= multiLineEndLength
                          && isComment(endText,
                                       endPos - multiLineEndLength,
                                       definition,
                                       &CommentDefinition::multiLineEnd));

        doMultiLineStyleUncomment = hasSelStart && hasSelEnd;
        doMultiLineStyleComment = !doMultiLineStyleUncomment
                                  && (hasLeadingCharacters
                                      || hasTrailingCharacters
                                      || !definition.hasSingleLineStyle()
                                      || (flag == BlockComment));
    } else if (!hasSelection && !definition.hasSingleLineStyle()) {

        QString text = startBlock.text().trimmed();
        doMultiLineStyleUncomment = text.startsWith(definition.multiLineStart())
                                    && text.endsWith(definition.multiLineEnd());
        doMultiLineStyleComment = !doMultiLineStyleUncomment && !text.isEmpty();

        start = startBlock.position();
        end = endBlock.position() + endBlock.length() - 1;

//.........这里部分代码省略.........